Costing of National STI Program Implementation for the Global STI Control Strategy for the Health Sector, 2016-2021.

INTRODUCTION: In 2016 the World Health Assembly adopted the global strategy on Sexually Transmitted Infections (STI) 2016-2021 aiming to reduce curable STIs by 90% by 2030. We costed scaling-up priority interventions to coverage targets. METHODS: Strategy-targeted declines in Chlamydia trachomatis, Neisseria gonorrhoeae, Treponema pallidum and Trichomonas vaginalis were applied to WHO-estimated regional burdens at 2012. Syndromic case management was costed for these curable STIs, symptomatic Herpes Simplex Virus 2 (HSV-2), and non-STI vaginal syndromes, with incrementally expanding etiologic diagnosis. Service unit costs were multiplied with clinic attendances and people targeted for screening or prevention, by income tier. Human papilloma virus (HPV) vaccination and screening were costed for coverage increasing to 60% of 10-year-old girls for vaccination, and 60% of women 30-49 years for twice-lifetime screening (including clinical follow-up for positive screens), by 2021. RESULTS: Strategy implementation will cost an estimated US$ 18.1 billion over 2016-2021 in 117 low- and middle-income countries. Cost drivers are HPV vaccination ($3.26 billion) and screening ($3.69 billion), adolescent chlamydia screening ($2.54 billion), and antenatal syphilis screening ($1.4 billion). Clinical management-of 18 million genital ulcers, 29-39 million urethral discharges and 42-53 million vaginal discharges annually-will cost $3.0 billion, including $818 million for service delivery and $1.4 billion for gonorrhea and chlamydia testing. Global costs increase from $2.6 billion to $ 4.0 billion over 2016-2021, driven by HPV services scale-up, despite vaccine price reduction. Sub-Saharan Africa, bearing 40% of curable STI burdens, covers 44% of global service needs and 30% of cost, the Western Pacific 15% of burden/need and 26% of cost, South-East Asia 20% of burden/need and 18% of cost. CONCLUSIONS: Costs of global STI control depend on price trends for HPV vaccines and chlamydia tests. Middle-income and especially low-income countries need increased investment, innovative financing, and synergizing with other health programs.

Optical coherence tomography for assessment of microbicide safety in a small animal model.

Sensitive imaging techniques for small animals are needed to assess drug toxicity in preclinical studies. Optical coherence tomography (OCT) provides a noninvasive tool for high-resolution, depth-resolved visualization of drug-induced changes in tissue morphology. In a mouse model, we utilize OCT to assess vaginal tissue integrity following the application of topical microbicides (drugs used to prevent infection). Mice are challenged with herpes simplex virus-2 (HSV-2) to determine the correlation of tissue damage as quantified by OCT to increased susceptibility. The microbicide benzalkonium chloride (BZK) (0.02, 0.2, or 2%) or phosphate buffered saline control is administered intravaginally. In vivo OCT imaging and collection of tissue samples are performed after treatment. A quantitative OCT scoring system is applied to assess epithelial damage, and the results are compared with those of histology. A separate group of mice are treated similarly then challenged with HSV-2. Epithelial morphology quantified noninvasively by OCT and histology are dose-dependent (p<0.0001). The OCT scoring system detected a significant increase in epithelial damage with increasing BZK concentration (p<0.0001). These results paralleled an increase in HSV-2 susceptibility (p<0.005). OCT can be used as a noninvasive tool to assess topical drug toxicity in a small animal model with potential to predict increased susceptibility to vaginal infection.

Bayesian adjustment for exposure misclassification in case-control studies.

Poor measurement of explanatory variables occurs frequently in observational studies. Error-prone observations may lead to biased estimation and loss of power in detecting the impact of explanatory variables on the response. We consider misclassified binary exposure in the context of case-control studies, assuming the availability of validation data to inform the magnitude of the misclassification. A Bayesian adjustment to correct the misclassification is investigated. Simulation studies show that the Bayesian method can have advantages over non-Bayesian counterparts, particularly in the face of a rare exposure, small validation sample sizes, and uncertainty about whether exposure misclassification is differential or non-differential. The method is illustrated via application to several real studies.